To assess circadian rhythm development & congenital cardiovascular disease risk, blood pressure (BP), heart rate (HR) & salivary aldosterone will be monitored for 48 hours after birth on 330 newborns. At 48 hours after birth, circulating aldosterone, TSH &DHEA-S & an echocardiogram will be determined. Parents & other accessible family members will contribute a 48-hours BP & HR profile with a fully ambulatory BP monitor or using specially-designed minimal sampling schemes that do not interfere with daily activities yet allow assessment of BP & HR dynamics, with a room-restricted monitor. A questionnaire will inquire notably about a family history of high BP & diabetes. All infants will be individually tracked, at equivalent or similar to 1.5-year intervals to provide up to 4 profiles (210 infants) between equivalent or similar to 0.5 and equivalent or similar to 4.5 years of age, for a 48-h BP, HR & salivary aldosterone profile, a blood aldosterone, TSH & DHEA-S & an echocardiogram. Chronobiologic analyses will 1) provide reference standards for trend-adjusted means & dynamic cardiovascular features including a chronobiologic index to recognize, at birth, the risk of developing a high BP later in life; 2) quantify age trends; 3) show relations among different (physiologic or imaging) cardiovascular & endocrine variables; 4) indicate the cost-effective neonatal predictor at birth of the follow-up BP & HR means & dynamic characteristics; & 5) compare, by the criterion of BP tracking, the relative merits of an anamnestic or quantitative (familial measurement-based) family history, the chronobiologic & conventional endpoints from familial BP & HP monitoring & the neonatal chronobiologic predictors of cardiovascular disease risk. Cluster analysis should answer the question whether a dynamic neonatal index classifies risk better than the best quantitative family history or BP profile. If so, a neonatal index would gauge the effect of intervention on the pregnant woman & underlie indications for individualized dietary intervention on the newborn.